blob: 5ac37bd024c8843c4619a052f0f35fcb945e1a76 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
// ISHTP interface for ChromeOS Embedded Controller
//
// Copyright (c) 2019, Intel Corporation.
//
// ISHTP client driver for talking to the Chrome OS EC firmware running
// on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol
// (ISH-TP).
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/intel-ish-client-if.h>
#include "cros_ec.h"
/*
* ISH TX/RX ring buffer pool size
*
* The AP->ISH messages and corresponding ISH->AP responses are
* serialized. We need 1 TX and 1 RX buffer for these.
*
* The MKBP ISH->AP events are serialized. We need one additional RX
* buffer for them.
*/
#define CROS_ISH_CL_TX_RING_SIZE 8
#define CROS_ISH_CL_RX_RING_SIZE 8
/* ISH CrOS EC Host Commands */
enum cros_ec_ish_channel {
CROS_EC_COMMAND = 1, /* AP->ISH message */
CROS_MKBP_EVENT = 2, /* ISH->AP events */
};
/*
* ISH firmware timeout for 1 message send failure is 1Hz, and the
* firmware will retry 2 times, so 3Hz is used for timeout.
*/
#define ISHTP_SEND_TIMEOUT (3 * HZ)
/* ISH Transport CrOS EC ISH client unique GUID */
static const struct ishtp_device_id cros_ec_ishtp_id_table[] = {
{ .guid = GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0), },
{ }
};
MODULE_DEVICE_TABLE(ishtp, cros_ec_ishtp_id_table);
struct header {
u8 channel;
u8 status;
u8 token;
u8 reserved;
} __packed;
struct cros_ish_out_msg {
struct header hdr;
struct ec_host_request ec_request;
} __packed;
struct cros_ish_in_msg {
struct header hdr;
struct ec_host_response ec_response;
} __packed;
#define IN_MSG_EC_RESPONSE_PREAMBLE \
offsetof(struct cros_ish_in_msg, ec_response)
#define OUT_MSG_EC_REQUEST_PREAMBLE \
offsetof(struct cros_ish_out_msg, ec_request)
#define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
/*
* The Read-Write Semaphore is used to prevent message TX or RX while
* the ishtp client is being initialized or undergoing reset.
*
* The readers are the kernel function calls responsible for IA->ISH
* and ISH->AP messaging.
*
* The writers are .reset() and .probe() function.
*/
static DECLARE_RWSEM(init_lock);
/**
* struct response_info - Encapsulate firmware response related
* information for passing between function ish_send() and
* process_recv() callback.
*
* @data: Copy the data received from firmware here.
* @max_size: Max size allocated for the @data buffer. If the received
* data exceeds this value, we log an error.
* @size: Actual size of data received from firmware.
* @error: 0 for success, negative error code for a failure in process_recv().
* @token: Expected token for response that we are waiting on.
* @received: Set to true on receiving a valid firmware response to host command
* @wait_queue: Wait queue for host to wait for firmware response.
*/
struct response_info {
void *data;
size_t max_size;
size_t size;
int error;
u8 token;
bool received;
wait_queue_head_t wait_queue;
};
/**
* struct ishtp_cl_data - Encapsulate per ISH TP Client.
*
* @cros_ish_cl: ISHTP firmware client instance.
* @cl_device: ISHTP client device instance.
* @response: Response info passing between ish_send() and process_recv().
* @work_ishtp_reset: Work queue reset handling.
* @work_ec_evt: Work queue for EC events.
* @ec_dev: CrOS EC MFD device.
*
* This structure is used to store per client data.
*/
struct ishtp_cl_data {
struct ishtp_cl *cros_ish_cl;
struct ishtp_cl_device *cl_device;
/*
* Used for passing firmware response information between
* ish_send() and process_recv() callback.
*/
struct response_info response;
struct work_struct work_ishtp_reset;
struct work_struct work_ec_evt;
struct cros_ec_device *ec_dev;
};
/**
* ish_evt_handler - ISH to AP event handler
* @work: Work struct
*/
static void ish_evt_handler(struct work_struct *work)
{
struct ishtp_cl_data *client_data =
container_of(work, struct ishtp_cl_data, work_ec_evt);
cros_ec_irq_thread(0, client_data->ec_dev);
}
/**
* ish_send() - Send message from host to firmware
*
* @client_data: Client data instance
* @out_msg: Message buffer to be sent to firmware
* @out_size: Size of out going message
* @in_msg: Message buffer where the incoming data is copied. This buffer
* is allocated by calling
* @in_size: Max size of incoming message
*
* Return: Number of bytes copied in the in_msg on success, negative
* error code on failure.
*/
static int ish_send(struct ishtp_cl_data *client_data,
u8 *out_msg, size_t out_size,
u8 *in_msg, size_t in_size)
{
static u8 next_token;
int rv;
struct header *out_hdr = (struct header *)out_msg;
struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
dev_dbg(cl_data_to_dev(client_data),
"%s: channel=%02u status=%02u\n",
__func__, out_hdr->channel, out_hdr->status);
/* Setup for incoming response */
client_data->response.data = in_msg;
client_data->response.max_size = in_size;
client_data->response.error = 0;
client_data->response.token = next_token++;
client_data->response.received = false;
out_hdr->token = client_data->response.token;
rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
if (rv) {
dev_err(cl_data_to_dev(client_data),
"ishtp_cl_send error %d\n", rv);
return rv;
}
wait_event_interruptible_timeout(client_data->response.wait_queue,
client_data->response.received,
ISHTP_SEND_TIMEOUT);
if (!client_data->response.received) {
dev_err(cl_data_to_dev(client_data),
"Timed out for response to host message\n");
return -ETIMEDOUT;
}
if (client_data->response.error < 0)
return client_data->response.error;
return client_data->response.size;
}
/**
* process_recv() - Received and parse incoming packet
* @cros_ish_cl: Client instance to get stats
* @rb_in_proc: Host interface message buffer
* @timestamp: Timestamp of when parent callback started
*
* Parse the incoming packet. If it is a response packet then it will
* update per instance flags and wake up the caller waiting to for the
* response. If it is an event packet then it will schedule event work.
*/
static void process_recv(struct ishtp_cl *cros_ish_cl,
struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp)
{
size_t data_len = rb_in_proc->buf_idx;
struct ishtp_cl_data *client_data =
ishtp_get_client_data(cros_ish_cl);
struct device *dev = cl_data_to_dev(client_data);
struct cros_ish_in_msg *in_msg =
(struct cros_ish_in_msg *)rb_in_proc->buffer.data;
/* Proceed only if reset or init is not in progress */
if (!down_read_trylock(&init_lock)) {
/* Free the buffer */
ishtp_cl_io_rb_recycle(rb_in_proc);
dev_warn(dev,
"Host is not ready to receive incoming messages\n");
return;
}
/*
* All firmware messages contain a header. Check the buffer size
* before accessing elements inside.
*/
if (!rb_in_proc->buffer.data) {
dev_warn(dev, "rb_in_proc->buffer.data returned null");
client_data->response.error = -EBADMSG;
goto end_error;
}
if (data_len < sizeof(struct header)) {
dev_err(dev, "data size %zu is less than header %zu\n",
data_len, sizeof(struct header));
client_data->response.error = -EMSGSIZE;
goto end_error;
}
dev_dbg(dev, "channel=%02u status=%02u\n",
in_msg->hdr.channel, in_msg->hdr.status);
switch (in_msg->hdr.channel) {
case CROS_EC_COMMAND:
if (client_data->response.received) {
dev_err(dev,
"Previous firmware message not yet processed\n");
goto end_error;
}
if (client_data->response.token != in_msg->hdr.token) {
dev_err_ratelimited(dev,
"Dropping old response token %d\n",
in_msg->hdr.token);
goto end_error;
}
/* Sanity check */
if (!client_data->response.data) {
dev_err(dev,
"Receiving buffer is null. Should be allocated by calling function\n");
client_data->response.error = -EINVAL;
goto error_wake_up;
}
if (data_len > client_data->response.max_size) {
dev_err(dev,
"Received buffer size %zu is larger than allocated buffer %zu\n",
data_len, client_data->response.max_size);
client_data->response.error = -EMSGSIZE;
goto error_wake_up;
}
if (in_msg->hdr.status) {
dev_err(dev, "firmware returned status %d\n",
in_msg->hdr.status);
client_data->response.error = -EIO;
goto error_wake_up;
}
/* Update the actual received buffer size */
client_data->response.size = data_len;
/*
* Copy the buffer received in firmware response for the
* calling thread.
*/
memcpy(client_data->response.data,
rb_in_proc->buffer.data, data_len);
error_wake_up:
/* Free the buffer since we copied data or didn't need it */
ishtp_cl_io_rb_recycle(rb_in_proc);
rb_in_proc = NULL;
/* Set flag before waking up the caller */
client_data->response.received = true;
/* Wake the calling thread */
wake_up_interruptible(&client_data->response.wait_queue);
break;
case CROS_MKBP_EVENT:
/* Free the buffer. This is just an event without data */
ishtp_cl_io_rb_recycle(rb_in_proc);
rb_in_proc = NULL;
/*
* Set timestamp from beginning of function since we actually
* got an incoming MKBP event
*/
client_data->ec_dev->last_event_time = timestamp;
schedule_work(&client_data->work_ec_evt);
break;
default:
dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
}
end_error:
/* Free the buffer if we already haven't */
if (rb_in_proc)
ishtp_cl_io_rb_recycle(rb_in_proc);
up_read(&init_lock);
}
/**
* ish_event_cb() - bus driver callback for incoming message
* @cl_device: ISHTP client device for which this message is targeted.
*
* Remove the packet from the list and process the message by calling
* process_recv.
*/
static void ish_event_cb(struct ishtp_cl_device *cl_device)
{
struct ishtp_cl_rb *rb_in_proc;
struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
ktime_t timestamp;
/*
* Take timestamp as close to hardware interrupt as possible for sensor
* timestamps.
*/
timestamp = cros_ec_get_time_ns();
while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
/* Decide what to do with received data */
process_recv(cros_ish_cl, rb_in_proc, timestamp);
}
}
/**
* cros_ish_init() - Init function for ISHTP client
* @cros_ish_cl: ISHTP client instance
* @reset: true if called from reset handler
*
* This function complete the initializtion of the client.
*
* Return: 0 for success, negative error code for failure.
*/
static int cros_ish_init(struct ishtp_cl *cros_ish_cl, bool reset)
{
int rv;
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
rv = ishtp_cl_establish_connection(cros_ish_cl,
&cros_ec_ishtp_id_table[0].guid,
CROS_ISH_CL_TX_RING_SIZE,
CROS_ISH_CL_RX_RING_SIZE,
reset);
if (rv) {
dev_err(cl_data_to_dev(client_data),
"client connect fail\n");
goto err_cl_disconnect;
}
ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
return 0;
err_cl_disconnect:
ishtp_cl_destroy_connection(cros_ish_cl, reset);
return rv;
}
/**
* cros_ish_deinit() - Deinit function for ISHTP client
* @cros_ish_cl: ISHTP client instance
*
* Unlink and free cros_ec client
*/
static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
{
ishtp_cl_destroy_connection(cros_ish_cl, false);
/* Disband and free all Tx and Rx client-level rings */
ishtp_cl_free(cros_ish_cl);
}
/**
* prepare_cros_ec_rx() - Check & prepare receive buffer
* @ec_dev: CrOS EC MFD device.
* @in_msg: Incoming message buffer
* @msg: cros_ec command used to send & receive data
*
* Return: 0 for success, negative error code for failure.
*
* Check the received buffer. Convert to cros_ec_command format.
*/
static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
const struct cros_ish_in_msg *in_msg,
struct cros_ec_command *msg)
{
u8 sum = 0;
int i, rv, offset;
/* Check response error code */
msg->result = in_msg->ec_response.result;
rv = cros_ec_check_result(ec_dev, msg);
if (rv < 0)
return rv;
if (in_msg->ec_response.data_len > msg->insize) {
dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
in_msg->ec_response.data_len, msg->insize);
return -ENOSPC;
}
/* Copy response packet payload and compute checksum */
for (i = 0; i < sizeof(struct ec_host_response); i++)
sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
offset = sizeof(struct cros_ish_in_msg);
for (i = 0; i < in_msg->ec_response.data_len; i++)
sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
if (sum) {
dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
return -EBADMSG;
}
return 0;
}
static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
int rv;
struct ishtp_cl *cros_ish_cl = ec_dev->priv;
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
struct device *dev = cl_data_to_dev(client_data);
struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
struct cros_ish_out_msg *out_msg =
(struct cros_ish_out_msg *)ec_dev->dout;
size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
/* Sanity checks */
if (in_size > ec_dev->din_size) {
dev_err(dev,
"Incoming payload size %zu is too large for ec_dev->din_size %d\n",
in_size, ec_dev->din_size);
return -EMSGSIZE;
}
if (out_size > ec_dev->dout_size) {
dev_err(dev,
"Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
out_size, ec_dev->dout_size);
return -EMSGSIZE;
}
/* Proceed only if reset-init is not in progress */
if (!down_read_trylock(&init_lock)) {
dev_warn(dev,
"Host is not ready to send messages to ISH. Try again\n");
return -EAGAIN;
}
/* Prepare the package to be sent over ISH TP */
out_msg->hdr.channel = CROS_EC_COMMAND;
out_msg->hdr.status = 0;
ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
rv = cros_ec_prepare_tx(ec_dev, msg);
if (rv < 0)
goto end_error;
ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
dev_dbg(dev,
"out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
out_msg->ec_request.struct_version,
out_msg->ec_request.checksum,
out_msg->ec_request.command,
out_msg->ec_request.command_version,
out_msg->ec_request.data_len);
/* Send command to ISH EC firmware and read response */
rv = ish_send(client_data,
(u8 *)out_msg, out_size,
(u8 *)in_msg, in_size);
if (rv < 0)
goto end_error;
rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
if (rv)
goto end_error;
rv = in_msg->ec_response.data_len;
dev_dbg(dev,
"in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
in_msg->ec_response.struct_version,
in_msg->ec_response.checksum,
in_msg->ec_response.result,
in_msg->ec_response.data_len);
end_error:
if (msg->command == EC_CMD_REBOOT_EC)
msleep(EC_REBOOT_DELAY_MS);
up_read(&init_lock);
return rv;
}
static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
{
struct cros_ec_device *ec_dev;
struct device *dev = cl_data_to_dev(client_data);
ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
if (!ec_dev)
return -ENOMEM;
client_data->ec_dev = ec_dev;
dev->driver_data = ec_dev;
ec_dev->dev = dev;
ec_dev->priv = client_data->cros_ish_cl;
ec_dev->cmd_xfer = NULL;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
ec_dev->phys_name = dev_name(dev);
ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
sizeof(struct ec_response_get_protocol_info);
ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
return cros_ec_register(ec_dev);
}
static void reset_handler(struct work_struct *work)
{
int rv;
struct device *dev;
struct ishtp_cl *cros_ish_cl;
struct ishtp_cl_data *client_data =
container_of(work, struct ishtp_cl_data, work_ishtp_reset);
/* Lock for reset to complete */
down_write(&init_lock);
cros_ish_cl = client_data->cros_ish_cl;
ishtp_cl_destroy_connection(cros_ish_cl, true);
rv = cros_ish_init(cros_ish_cl, true);
if (rv) {
dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
up_write(&init_lock);
return;
}
/* Refresh ec_dev device pointers */
client_data->ec_dev->priv = client_data->cros_ish_cl;
dev = cl_data_to_dev(client_data);
dev->driver_data = client_data->ec_dev;
dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
up_write(&init_lock);
}
/**
* cros_ec_ishtp_probe() - ISHTP client driver probe callback
* @cl_device: ISHTP client device instance
*
* Return: 0 for success, negative error code for failure.
*/
static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
{
int rv;
struct ishtp_cl *cros_ish_cl;
struct ishtp_cl_data *client_data =
devm_kzalloc(ishtp_device(cl_device),
sizeof(*client_data), GFP_KERNEL);
if (!client_data)
return -ENOMEM;
/* Lock for initialization to complete */
down_write(&init_lock);
cros_ish_cl = ishtp_cl_allocate(cl_device);
if (!cros_ish_cl) {
rv = -ENOMEM;
goto end_ishtp_cl_alloc_error;
}
ishtp_set_drvdata(cl_device, cros_ish_cl);
ishtp_set_client_data(cros_ish_cl, client_data);
client_data->cros_ish_cl = cros_ish_cl;
client_data->cl_device = cl_device;
init_waitqueue_head(&client_data->response.wait_queue);
INIT_WORK(&client_data->work_ishtp_reset,
reset_handler);
INIT_WORK(&client_data->work_ec_evt,
ish_evt_handler);
rv = cros_ish_init(cros_ish_cl, false);
if (rv)
goto end_ishtp_cl_init_error;
ishtp_get_device(cl_device);
up_write(&init_lock);
/* Register croc_ec_dev mfd */
rv = cros_ec_dev_init(client_data);
if (rv) {
down_write(&init_lock);
goto end_cros_ec_dev_init_error;
}
return 0;
end_cros_ec_dev_init_error:
ishtp_cl_destroy_connection(cros_ish_cl, false);
ishtp_put_device(cl_device);
end_ishtp_cl_init_error:
ishtp_cl_free(cros_ish_cl);
end_ishtp_cl_alloc_error:
up_write(&init_lock);
return rv;
}
/**
* cros_ec_ishtp_remove() - ISHTP client driver remove callback
* @cl_device: ISHTP client device instance
*
* Return: 0
*/
static void cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
{
struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
cancel_work_sync(&client_data->work_ishtp_reset);
cancel_work_sync(&client_data->work_ec_evt);
cros_ish_deinit(cros_ish_cl);
ishtp_put_device(cl_device);
}
/**
* cros_ec_ishtp_reset() - ISHTP client driver reset callback
* @cl_device: ISHTP client device instance
*
* Return: 0
*/
static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
{
struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
schedule_work(&client_data->work_ishtp_reset);
return 0;
}
/**
* cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
* @device: device instance
*
* Return: 0 for success, negative error code for failure.
*/
static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
{
struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
return cros_ec_suspend(client_data->ec_dev);
}
/**
* cros_ec_ishtp_resume() - ISHTP client driver resume callback
* @device: device instance
*
* Return: 0 for success, negative error code for failure.
*/
static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
{
struct ishtp_cl_device *cl_device = ishtp_dev_to_cl_device(device);
struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
return cros_ec_resume(client_data->ec_dev);
}
static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
cros_ec_ishtp_resume);
static struct ishtp_cl_driver cros_ec_ishtp_driver = {
.name = "cros_ec_ishtp",
.id = cros_ec_ishtp_id_table,
.probe = cros_ec_ishtp_probe,
.remove = cros_ec_ishtp_remove,
.reset = cros_ec_ishtp_reset,
.driver = {
.pm = &cros_ec_ishtp_pm_ops,
},
};
static int __init cros_ec_ishtp_mod_init(void)
{
return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
}
static void __exit cros_ec_ishtp_mod_exit(void)
{
ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
}
module_init(cros_ec_ishtp_mod_init);
module_exit(cros_ec_ishtp_mod_exit);
MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@intel.com>");
MODULE_LICENSE("GPL v2");